Check valve for a heavy duty pump



May 9, 1961 F. A. BYNUM CHECK VALVE FOR A HEAVY DUTY PUMP Filed Feb. 3.1958 VALVE POT COVER ASSEMBLY FROM PISTON CYLINDER m T m V m FRANK A.BYNUM,

ATTORNEY United states Pa CHECK vALvE FOR A HEAVY DUTY PUMP Frank A.Bynum, Duncan, 0kla., assignor to Halllburton Company, a corporation ofDelaware Filed Feb. 3, 1958, Ser. No. 712,761

1 Claim. (Cl. 137-54323) This invention relates to check valves, andmore particularly to check valves adapted for use in heavy duty pumps,such as those used in the oil fields for forcing cement slurry, mud orother abrasive fluid into a well under high pressure.

Some of the problems encountered in attempting to provide a suitablepump for use in the oil fields are set forth in the U.S. Patent toOwsley, No. 2,216,57 3, granted October 1, 1940. Cement slurry isabrasive, heavy and viscous, and, unless it is kept in motion it is aptto lodge and solidify.

Particular care must be exercised in the construction of the valves andvalve pots for oil field pumps. The arrangement illustrated in the abovementioned Owsley patent has been found to be very well suited for thisuse. As there shown, both the suction and discharge valves of a pump areso designed that the fluid enters at the bottom of the pot and flowsupwardly and out without a reversal of direction so that there is littletendency for the fluid to remain stationary, and the internal efficiencyof the valves is good.

The check valves of the present invention incorporate certainimprovements over the valves shown in the above mentioned Owsley patent,and are adapted for use in a pump like that illustrated therein, or inother pumps in which similar problems are encountered.

Where abrasive fluids are being pumped through a valve, there isconsiderable wear both on the valve body and on its seat, and theseparts have to be replaced frequently. The-structure of the pot should besuch that this can be done conveniently and rapidly. If a valve startsto leak excessively during the process of cementing a well, these partsmay have to be replaced in the field, and the operation suspended whilethis is done, with the consequent hazard that the cement slurry willtake an initial set unless the valve is repaired in a very short periodof time.

In accordance with the present invention, both the valve body and itsseat are mounted in the valve pot directly beneath the cover. They arenot secured by threads or bolts, but are held in place by a frictionring. The cover is of a diameter sufficiently large to permit the valveseat and valve body to be pulled out with a simple screw jack or similartool. Also, the structure of the valve seat and the mounting for thevalve body are such that the valve body is properly centered withrespect to the seat, and this remains true as these parts are replaced,even though the replacing operation is performed in a hurry or by oneunskilled in performing the operation.

The objects of the invention will be clear from the above outline andfrom the following specification when taken in connection with theaccompanying drawing, in which:

Figure 1 is a view invertical cross section of a valve seat, a valvebody and mounting means constructed in accordance with the invention,and with a valve pot and cover shown in dotted lines, and Figure 2 is atransverse cross-sectional view of'the apparatus of Figure 1, taken onthe line 22 thereof.

Referring to the drawing in detail, it will be seen that the valve seatconsists of a ring 10 having a cylindrical outer surface. This ring 10has a beveled upper edge 11, which constitutes the valve seat. It ismounted in a cylindrical recess 12 of the valve pot 13.

The recess 12 is only slightly larger in diameter than the outsidediameter of the ring 10, and interposed between the ring 10 and the wallof the recess 12 is a copper friction bushing 14. The parts are of suchdimensions that the ring 10 is tightly held in the recess 12 by thebushing 14, this manner of mounting being called an interference fit,the copper deforming slightly as the pants are pressed into the recess12.

There is an O-ring 15, of rubber or the like, fitted into a suitablegroove on the ring 10 above the bushing 14, to prevent any leakage alongthe outside of the ring 10 between it and the wall of the recess 12.

Mounted in the recess 12 beneath the ring 10, and also frictionally heldby the bushing 14, is a spider 16 which serves as a guide for the stem17 of the valve body 18.

The spider 16 has the outer ends of its spokes shaped to conform to thebottom of the ring 10, as shown in Figure l, and it also fits snugly inthe recess 12 beneath the ring 10 and the bushing 14, the diameter ofthe spider being approximately the same as the outside diameter of thebushing 14.

The hub of the spider 16 contains a ferrule 20, of rubber or the like,which is bonded to a smaller copper bushing 21 press fitted into acentral bore through the spider. The ferrule 20 is vertically grooved toprovide inwardly projecting lands 22, as shown in Figure 2, which are incontact with and serve as a guide for the stem 17 of the valve body.There is thus little tendency for the valve to become stuck even thoughthe fluid being pumped contains debris, sand or abrasive material.

The valve body 18 is, of course, provided with a beveled outer rim toconform to the shape of the valve seat 11. In addition, it is providedwith a rubber gasket 23, the lower edge of which also conforms to theshape of the valve seat, as shown in Figure 1, this gasket being securedto the valve body by a suitable flanged washer 24 and its clamp 25.

A coil spring 26 is mounted between the valve pot cover and the valvebody 18 to exert downward force upon the valve body and tend to keep thevalve closed during operation, in accordance with the usual practice.

Should the valve become worn excessively, it will be seen that the valveseat 10, the spider 16 and the valve body 18 can readily be removed andreplaced. All that is necessary to perform this operation is to removethe pot cover and the spring 26, and then, apply a suitable hook to thespider 16 and pull the entire assembly out of the valve pot. If desired,a suitable screw jack may be placed upon the valve pot to exert thenecessary lifting force on the hook.

A new valve seat, valve body and mounting means may then be pressed intothe recess 12, and the valve placed back in operation in a very shortperiod of time.

While only one embodiment of the invention has been shown and describedherein, it will be obvious that var-ions changes may be made withoutdeparting from the spirit of the invention or the scope of the annexedclaim.

I claim:

A check valve assembly comprising a valve pot suitable for use in aheavy duty pump, said pot having a recess, a ring mounted in said recessand having a beveled upper edge to provide a valve seat, a separatespider member mounted in said recess beneath said ring and provided witha centrally located bore therein, a securing bushing surfounding aportion of said ring and frictionally securing both the ring and the sider member to said valve p61, a valve body adapted to rest upon saidvalve seat, said valve body having a stemgrojectingdownwardly throughthebore of sai'cl'spi'de'r ifir'r'iber and, means serving as a guide forsaid sternand valve body, saidniea'ns' inelildinga ferrule of flexiblematerial and having verticallyextending grooves to provide lands'Which'are in Contact with said stem and serve to center the valvebodywithrespect to its seat, and the entire assembly being suchjthat'thering and spider member may be snuglyfitted into the recess in the valvepot, but be readily'pulled out of the valve pot for replacement.

References Cited in the file of this patent UNITED STATES PATENTS'

